A5011380769- Gold and Silver Nanoparticles Synthesis and Applications
- ZnO doping and properties
- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
- Iron oxide chemistry and applications
- Nanocluster Synthesis and Applications
- Multiferroics and related materials
- X-ray Diffraction in Crystallography
- Glass properties and applications
- Quantum Dots Synthesis And Properties
- Luminescence Properties of Advanced Materials
- Characterization and Applications of Magnetic Nanoparticles
- Crystallization and Solubility Studies
- Analytical Chemistry and Sensors
- Plasmonic and Surface Plasmon Research
- Advanced Condensed Matter Physics
- Copper-based nanomaterials and applications
- Laser-Ablation Synthesis of Nanoparticles
- Electronic and Structural Properties of Oxides
- Nanoparticle-Based Drug Delivery
- Ferroelectric and Piezoelectric Materials
- Molecular Junctions and Nanostructures
- Magnetic Properties and Applications
- Magnetic Properties and Synthesis of Ferrites
- Quantum and electron transport phenomena
Instituto de Cerámica y Vidrio
2015-2024
Consejo Superior de Investigaciones Científicas
2011-2023
The University of Texas Rio Grande Valley
2023
University of Wisconsin–Madison
2023
Universidad Nebrija
2023
Pontifical Catholic University of Peru
2023
Universidad de Jaén
2022
University of California, Riverside
2017-2022
Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán
2021
Instituto Nacional de Ecología y Cambio Climático
2020
The excitation of surface plasmons (SPs) in metallic nanoparticles (NPs) induces optical properties hardly achievable other materials, yielding a wide range applications many fields. This review presents an overview SPs NPs. concept NPs is qualitatively described using comparison with simple linear oscillators. mathematical models to carry on calculations are presented as well the most common approximations. different parameters governing features and their effect materials reviewed....
We report on the experimental observation of magnetic hysteresis up to room temperature in thiol-capped Au nanoparticles with 1.4 nm size. The coercive field ranges from 860 Oe at 5 K 250 300 K. It is estimated that atoms exhibit a moment mu=0.036mu(B). However, similar size but stabilized by means surfactant, i.e., weak interaction between protective molecules and surface atoms, are diamagnetic, as bulk samples are. apparent ferromagnetism consequently associated 5d localized holes...
We experimentally show that it is possible to induce room-temperature ferromagnetic-like behavior in ZnO nanoparticles without doping with magnetic impurities but simply inducing an alteration of their electronic configuration. Capping ( approximately 10 nm size) different organic molecules produces configuration depends on the particular molecule, as evidenced by photoluminescence and X-ray absorption spectroscopies altering properties varies from diamagnetic behavior.
Local heating can be produced by iron oxide nanoparticles (IONPs) when exposed to an alternating magnetic field (AMF). To measure the temperature profile at nanoparticle surface with a subnanometer resolution, here we present molecular probe based on thermal decomposition of thermo-sensitive molecule, namely, azobis[N-(2-carboxyethyl)-2-methylpropionamidine]. Fluoresceineamine (FA) was bound azo molecule IONP functionalized poly(ethylene glycol) (PEG) spacers different weights. Significant...
Dumbbell-like Au-Fe3O4 nanoparticles and their single-component counterparts, Au Fe3O4, were compared regarding H2O2 reduction capability. The are catalytically more active, which is attributed to polarization effects from Fe3O4. This activity can be further tuned by the size of nanoparticles. Detailed facts importance specialist readers published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted authors. Please note:...
In this Letter, we experimentally show that the room temperature ferromagnetism in Mn-Zn-O system recently observed is associated with coexistence of ${\mathrm{Mn}}^{3+}$ and ${\mathrm{Mn}}^{4+}$ via a double-exchange mechanism. The presence ZnO around ${\mathrm{MnO}}_{2}$ modifies kinetics ${\mathrm{MnO}}_{2}\ensuremath{\rightarrow}{\mathrm{Mn}}_{2}{\mathrm{O}}_{3}$ reduction favors both Mn oxidation states. ferromagnetic phase interface formed at Zn diffusion front into oxide, corroborated...
It has been recently reported that some nonmagnetic materials in bulk state exhibit magnetic behavior at the nanoscale due to surface and size effects. The experimental observation of these effects is based on measurement very small signals. Thus, spurious are not critical for with large signals may become important when measuring (typically below 10−4emu). Here, we summarize sources should be considered studying this new nanomagnetism.
The origin of orbital magnetism recently observed in different nanostructured films and particles is discussed as a consequence spin-orbit coupling. It shown that contact potentials induced at the thin film surface by broken symmetries, domain boundaries self-assembled monolayers, lead to states some cases are large radius. component angular momentum normal can reach very high values decrease total energy decreasing interaction energy. Intraorbital ferromagnetic spin correlations induce...
Colloidal semiconductor-magnetic hybrid nanocrystals with topologically controlled composition are fabricated by heterogeneous nucleation of spherical epsilon-Co domains onto anatase TiO2 nanorods. The latter can be selectively decorated at either their tips or multiple locations along longitudinal sidewalls, forming lattice-matched heterointerfaces regardless the metal deposition sites. possibility switching between heterostructure growth modes arises from facet-dependent chemical...
Monodisperse cubic spinel iron oxide magnetic nanoparticles with variable sizes were prepared following a multi-injection seeded-growth approach. As expected from such well-known synthetic route, all samples characterized by narrow size distributions, and showed excellent stability in both organic aqueous media without the presence of aggregates, thus becoming ideal candidates for study their hyperthermia performance. Specific Loss Power measurements indicated low heating powers maximum any...
A colloidal nonaqueous approach to semiconductor-magnetic hybrid nanocrystals (HNCs) with selectable heterodimer topologies and tunable geometric parameters is demonstrated. Brookite TiO(2) nanorods, distinguished by a curved shape-tapered profile richly faceted terminations, are exploited as substrate seeds onto which single spherical domain of inverse spinel iron oxide can be epitaxially grown at either one apex or any location along their longitudinal sidewalls in hot surfactant...
Ti-doped BiFeO3 ceramics prepared by a mixed-oxide route were structurally characterized X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), and high-resolution transmission (HRTEM), giving evidence of the formation an inner structure at nanometric scale. The observed nanograins are separated Ti-rich areas that originate due to tendency titanium dopant segregate from perovskite lattice. Such peculiar nanostructure is responsible for changes produced in both electrical...
Tetrapod-shaped maghemite nanocrystals are synthesized by manipulating the decomposition of iron pentacarbonyl in a ternary surfactant mixture under mild thermal conditions. Adjustment reaction parameters allows for systematic tuning both width and length tetrapod arms, which grow preferentially along 111 easy axis direction. Such degree control leads to modulation magnetic behavior nanocrystals, evolves systematically as their surface magnetization phase shape anisotropy progressively increased.
We present here a study on the surface plasmon resonance (SPR) in Au films deposited onto glass substrates and annealed air at different temperatures. The initial exhibit resonant absorption of extended plasmons which depends film thickness. Thermal treatments promote modification continuous toward formation isolated islands. morphological features islands depend thickness annealing temperature. optical properties are qualitatively modified as consequence changes. For with below 30 nm,...
In this Rapid Communication we show the relationship between surface plasmon resonance damping and intensity of bonding for capped Au nanoparticles, (NPs). Up to now influence capping has been included as a phenomenological modification scattering constant. It is indicated here that effective NP size parameter mainly affected by bonding. Experimental results in different Au-thiol NPs are shown be excellent agreement with expression propose damping. Moreover, according our model profile gives...
The kinetics of acetylene hydrogenation in the presence a large excess ethylene was studied laboratory flow reactor. Experiments were carried out using Pd/α-Al2O3 commercial catalyst and simulated cracker gas mixture (H2/C2H2 = 50; 60% C2H4; 30% H2, traces CO), at varying temperature (293−393 K) pressure (2−35 atm). Competing mechanisms for formulated corresponding kinetic equations derived by rate-determining step methods. A criterion based upon statistical analysis used to discriminate...
We report the observation of negative nonlocal resistances in multiterminal mesoscopic gold Hall bar structures whose characteristic dimensions are larger than electron mean-free path. Our results can only be partially explained by a classical diffusive model transport, and not consistent with recently proposed based on spin effects. Instead, our analysis suggests that quasiballistic transport mechanism is responsible for observed resistance. Based sensitivity measurements effect model, we...
Hantelförmige Au-Fe3O4-Nanopartikel und ihre separaten Gegenstücke, Au Fe3O4, wurden hinsichtlich ihrer Effizienz bei der H2O2-Reduktion verglichen. Die höhere Aktivität wird auf die Polarisation von Fe3O4 durch zurückgeführt. lässt sich außerdem noch über Nanopartikelgröße einstellen. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted by the authors. Please...
We present here direct experimental evidence of the magnetic polarization Zn atoms in ZnO nanoparticles capped with different materials by means x-ray circular dichroism (XMCD). Our results demonstrate that magnetism this material is intrinsic and relays conduction band. The analysis both absorption spectroscopy XMCD signals points out formation a well-defined interface between capping molecule which exotic arises at hybridized band formed among bonding atom molecule. properties these...